aarch64: Add supports for FEAT_PoPS feature and DC instructions.
This patch add support for FEAT_PoPS feature which can be enabled
through +pops command line flag.
This patch also adds support for following DC instructions and the
spec can be found here [1].
1. "dc cigdvaps" enabled on passing +memtag+pops command line flags.
2. "dc civaps" enabled on passing +pops command line flag.
Andrew Burgess [Tue, 17 Jun 2025 16:39:36 +0000 (17:39 +0100)]
gdb: remove final m_stream->emit_style_escape calls from pager_file
After the last commit there were still a couple of calls to
m_stream->emit_style_escape in the pager_file class. As discussed in
the last commit, these are likely wrong, but I'd not been able to
produce any bugs because of them.
The reason why there are no bugs is that these calls are, I think,
entirely redundant. Consider this block:
if (m_wrap_column)
{
/* We are about to insert a newline at an historic
location in the WRAP_BUFFER. Before we do we want to
restore the default style. To know if we actually
need to insert an escape sequence we must restore the
current applied style to how it was at the WRAP_COLUMN
location. */
m_applied_style = m_wrap_style;
m_stream->emit_style_escape (ui_file_style ());
/* If we aren't actually wrapping, don't output
newline -- if chars_per_line is right, we
probably just overflowed anyway; if it's wrong,
let us keep going. */
m_stream->puts ("\n");
}
What we know (see previous commit) is that the call:
m_stream->emit_style_escape (ui_file_style ());
is dangerous as m_stream->m_applied_style is going to be out of sync
with its current state. Actually, m_stream->m_applied_style is likely
to be the default style as it is not updated elsewhere. So why does
this not cause problems?
Well, GDB's style output is always done in tightly scoped regions.
That means if we want to print some styled output, and then apply a
wrap point the code might look like this:
But, after printing 'some text', the style of gdb_stdout will have
returned to the default style.
My claim is that, whenever we encounter a wrap_here call, the stream
in question will _always_ have been returned to the default style.
This means that, in the block above, the call:
m_stream->emit_style_escape (ui_file_style ());
will never emit anything because it depends on a check against
m_stream->m_applied_style, which will always mean that the above call
does nothing. But that's OK. By chance, we'll have always placed the
stream into a default style state anyway, so no harm done.
Similarly, the other call:
/* Having finished inserting the wrapping we should
restore the style as it was at the WRAP_COLUMN. */
m_stream->emit_style_escape (m_wrap_style);
Tries to return m_stream to the state it was in at the point of the
wrap_here call. But, as described above, this will always be the
default style, so the above call will do nothing, but that just
happens to be exactly what we want!
So what does this commit do?
Well, I "fix" the above code by removing the
m_stream->emit_style_escape calls and replacing them with calls to
puts, passing in the escape sequence for the required style, but only
if the m_stream style as tracked by pager_file::m_stream_style
indicates this is needed.
Got the reasons given above, this should mean there is no change after
this patch. We still shouldn't be emitting any extra escape
sequences. But, should we ever manage to get into a state where we
call wrap_here with a stream in a style other than the default, then
this should mean things work as expected.
There should be no user visible changes after this commit.
Andrew Burgess [Mon, 16 Jun 2025 16:20:57 +0000 (17:20 +0100)]
gdb: styling fixes around and for the pagination prompt
This commit fixes a couple of issues relating to the pagination
prompt and styling. The pagination prompt is this one:
--Type <RET> for more, q to quit, c to continue without paging--
I did try to split this into multiple patches, based on the three
issues I describe below, but in the end, the fixes were all too
interconnected, so it ended up as one patch that makes two related,
but slightly different changes:
1. Within the pager_file class, relying on the m_applied_style
attribute of the wrapped m_stream, as is done when calling
m_stream->emit_style_escape, is not correct, so stop doing that, and
2. Failing to update m_applied_style within the pager_file class can
leave that attribute out of date, which can then lead to styling
errors later on, so ensure m_applied_style is always updated.
The problems I have seen are:
1. After quitting from a pagination prompt, the next command can
incorrectly style its output. This was reported as bug PR
gdb/31033, and is fixed by this commit.
2. The pagination prompt itself could be styled. The pagination
prompt should always be shown in the default style.
3. After continuing the output at a pagination prompt, GDB can fail
to restore the default style the next time the output (within the
same command) switches back to the default style.
There are tests for all these issues as part of this patch.
The pager_file class is a sub-class of wrapped_file, this means that a
pager_file is itself a ui_file, while it also manages a pointer to a
ui_file object (called m_stream). An instance of pager_file can be
installed as the gdb_stdout ui_file object.
Output sent to a pager_file is stored within an internal
buffer (called m_wrap_buffer) until we have a complete line, when the
content is flushed to the wrapped m_stream. If sufficient lines have
been written out then the pager_file will present the pagination
prompt and allow the user to continue viewing output, or quit the
current command.
As a pager_file is a ui_file, it has an m_applied_style member
variable.
The managed stream (m_stream) is also a ui_file, and so also has an
m_applied_style member variable.
In some places within the pager_file class we attempt to change the
current style of the m_stream using calls like this:
m_stream->emit_style_escape (style);
See pager_file::emit_style_escape, pager_file::prompt_for_continue,
and pager_file::puts. These calls will end up in
ui_file::emit_style_escape, which tries to skip emitting unnecessary
style escapes by checking if the requested style matches the current
m_applied_style value.
The m_applied_style value is updated by calls to the emit_style_escape
function.
The problem here is that most of the time pager_file doesn't change
the style of m_stream by calling m_stream->emit_style_escape. Most of
the time, style changes are performed by pager_file writing the escape
sequence into m_wrap_buffer, and then later flushing this buffer to
m_stream by calling m_stream->puts.
It has to be done this way. Calling m_stream->emit_style_escape
would, if it actually changed the style, immediately change the style
by emitting an escape sequence. But pager_file doesn't want that, it
wants the style change to happen later, when m_wrap_buffer is
flushed.
To avoid excessive style escape sequences being written into
m_wrap_buffer, the pager_file::m_applied_style performs a function
similar to the m_applied_style within m_stream, it tracks the current
style for the end of m_wrap_buffer, and only allows style escape
sequences to be emitted if the style is actually changing.
However, a consequence of this is the m_applied_style within m_stream,
is not updated, which means it will be out of sync with the actual
current style of m_stream. If we then try to make a call to
m_stream->emit_style_escape, if the style we are changing too happens
to match the out of date style in m_stream->m_applied_style, then the
style change will be ignored.
And this is indeed what we see in pager_file::prompt_for_continue with
the call:
m_stream->emit_style_escape (ui_file_style ());
As m_stream->m_applied_style is not being updated, it will always be
the default style, however m_stream itself might not actually be in
the default style. This call then will not emit an escape sequence as
the desired style matches the out of date m_applied_style.
The fix in this case is to call m_stream->puts directly, passing in
the escape sequence for the desired style. This will result in an
immediate change of style for m_stream, which fixes some of the
problems described above.
In fact, given that m_stream's m_applied_style is always going to be
out of sync, I think we should change all of the
m_stream->emit_style_escape calls to instead call m_stream->puts.
However, just changing to use puts doesn't fix all the problems.
I found that, if I run 'apropos time', then quit at the first
pagination prompt. If for the next command I run 'maintenance time' I
see the expected output:
"maintenance time" takes a numeric argument.
However, everything after the first double quote is given the command
name style rather than only styling the text between the double
quotes.
Here is GDB's stack while printing the above output:
#2 0x0000000001050d56 in ui_out::vmessage (this=0x7fff1238a150, in_style=..., format=0x1c05af0 "", args=0x7fff1238a288) at ../../src/gdb/ui-out.c:754
#3 0x000000000104db88 in ui_file::vprintf (this=0x3f9edb0, format=0x1c05ad0 "\"%ps\" takes a numeric argument.\n", args=0x7fff1238a288) at ../../src/gdb/ui-file.c:73
#4 0x00000000010bc754 in gdb_vprintf (stream=0x3f9edb0, format=0x1c05ad0 "\"%ps\" takes a numeric argument.\n", args=0x7fff1238a288) at ../../src/gdb/utils.c:1905
#5 0x00000000010bca20 in gdb_printf (format=0x1c05ad0 "\"%ps\" takes a numeric argument.\n") at ../../src/gdb/utils.c:1945
#6 0x0000000000b6b29e in maintenance_time_display (args=0x0, from_tty=1) at ../../src/gdb/maint.c:128
The interesting frames here are #3, in here `this` is the pager_file
for GDB's stdout, and this passes its m_applied_style to frame #2 as
the `in_style` argument.
If the m_applied_style is wrong, then frame #2 will believe that the
wrong style is currently in use as the default style, and so, after
printing 'maintenance time' GDB will switch back to the wrong style.
So the question is, why is pager_file::m_applied_style wrong?
In pager_file::prompt_for_continue, there is an attempt to switch back
to the default style using:
m_stream->emit_style_escape (ui_file_style ());
If this is changed to a puts call (see above) then this still leaves
pager_file::m_applied_style out of date.
The right fix in this case is, I think, to instead do this:
this->emit_style_escape (ui_file_style ());
this will update pager_file::m_applied_style, and also send the
default style to m_stream using a puts call.
While writing the tests I noticed that I was getting unnecessary style
reset sequences emitted.
The problem is that, around pagination, we don't really know what
style is currently applied to m_stream. The
pager_file::m_applied_style tracks the style at the end of
m_wrap_buffer, but this can run ahead of the current m_stream style.
For example, if the screen is currently full, such that the next
character of output will trigger the pagination prompt, if the next
call is actually to pager_file::emit_style_escape, then
pager_file::m_applied_style will be updated, but the style of m_stream
will remain unchanged. When the next character is written to
pager_file::puts then the pagination prompt will be presented, and GDB
will try to switch m_stream back to the default style. Whether an
escape is emitted or not will depend on the m_applied_style value,
which we know is different than the actual style of m_stream.
It is, after all, only when m_wrap_buffer is flushed to m_stream that
the style of m_stream actually change.
And so, this commit also adds pager_file::m_stream_style. This new
variable tracks the current style of m_stream. This really is a
replacement for m_stream's ui_file::m_applied_style, which is not
accessible from pager_file.
When content is flushed from m_wrap_buffer to m_stream then the
current value of pager_file::m_applied_style becomes the current style
of m_stream. But, when m_wrap_buffer is filling up, but before it is
flushed, then pager_file::m_applied_style can change, but
m_stream_style will remain unchanged.
Now in pager_file::emit_style_escape we are able to skip some of the
direct calls to m_stream->puts() used to emit style escapes.
After all this there are still a few calls to
m_stream->emit_style_escape(). These are all in the wrap_here support
code. I think that these calls are technically broken, but don't
actually cause any issues due to the way styling works in GDB. I
certainly haven't been able to trigger any bugs from these calls yet.
I plan to "fix" these in the next commit just for completeness.
Matthieu Longo [Thu, 17 Apr 2025 08:11:24 +0000 (09:11 +0100)]
readelf: invalid error message triggered when last tag is an empty string
Disclaimer: this issue cannot occur with Object Attributes v1 (OAv1) while
using the GNU binutils because a value of '\0' (empty string) for a tag
with a string value is considered as the default value for the attribute,
and consequently is eliminated by gas from the output object file during
the serialization.
An empty string is a valid value for a NTBS tag in both OAv1 and OAv2 [1]
cases. However, contrarily to OAv1, a OAv2 subsection can be required and
so, tags in this subsection might have to be present even if the value is
the default. To comply with this requirement, the OAv2 serializer won't
drop the default values.
In the case where a NTBS tag has the value '\0' and is last in the object
attributes section, the current code in readelf used for dumping the object
attributes incorrectly detects an overflow, and prints out an error message
for a corrupted string tag.
This patch fixes the detection of the overflow so that it now accept an
empty string in the last tag of the object attributes section.
It also fixes the previous tests for the empty NTBS case and the non-null
terminated string one. The fix was also tested in the context of OAv2's
patch series [1] where the issue was originally detected. No regression
was found.
Matthieu Longo [Fri, 20 Jun 2025 11:24:58 +0000 (12:24 +0100)]
arm testsuite: add two corner cases for EABI string attributes
The current testsuite for gas/readelf lacked two tests for EABI build
attributes:
- one when the final attribute is an empty string.
- one when the final attribute is a string missing the NULL terminator.
Those two issues cannot occur with Object Attributes v1 (OAv1) sections
created by the GNU binutils. Indeed a value of '\0' (empty string) for a
tag with a string value is considered as the default value for the
attribute, and consequently is eliminated by Gas from the output object
file during the serialization.
However, readelf should be able to process correctly files of an unknown
origin that could contain those two use cases.
This patch adds the two tests mentioned above. The first one is marked
as XFAIL because the empty string is not processed correctly by readelf
when it is in the last position. The second one passes, but simply print
out "[...]" without mentioning that the NTBS is corrupted.
A following patch will fix the bug in readelf, and will amend the newly
introduced tests.
Tom de Vries [Wed, 25 Jun 2025 07:39:30 +0000 (09:39 +0200)]
[gdb/testsuite] Fix gdb.base/infcall-failure.exp on freebsd
On x86_64-freebsd with test-case gdb.base/infcall-failure.exp I get:
...
(gdb) continue
Continuing.
Program received signal SIGSEGV, Segmentation fault.
Address not mapped to object.
0x0000000000400522 in func_segfault () at infcall-failure.c:24
24 return *p; /* Segfault here. */
Error in testing condition for breakpoint 2:
The program being debugged was signaled while in a function called from GDB.
GDB remains in the frame where the signal was received.
To change this behavior use "set unwind-on-signal on".
Evaluation of the expression containing the function
(func_segfault) will be abandoned.
When the function is done executing, GDB will silently stop.
(gdb) FAIL: $exp: target_async=on: target_non_stop=on: \
run_cond_hits_segfault_test: continue
...
The problem is that the regexp in the test-case doesn't expect the
"Address not mapped to object." bit.
Fix this by updating the regexp.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Tested on x86_64-freebsd and x86_64-linux.
Tom de Vries [Tue, 24 Jun 2025 15:17:38 +0000 (17:17 +0200)]
[gdb/testsuite] Make gdb.dap/log-message.exp more robust
PR testsuite/31831 reports the following failure in the
gdb.dap/log-message.exp test-case (formatted for readability):
...
{ "type": "event",
"event": "output",
"body": {
"category": "stdout",
"output": "Breakpoint 1 at 0x681: file log-message.c, line 23.\n"
},
"seq": 13
}
FAIL: $exp: logging output (checking body category)
...
for a gdb 14.2 based package.
The output event listed above is a result from the setBreakpoints request.
The test-case issues the setBreakpoints request and waits for the
corresponding response, but doesn't wait for the output event, and
consequently the output event is read by:
...
dap_wait_for_event_and_check "logging output" output \
{body category} console \
{body output} "got 23 - 23 = 0"
...
which triggers the failure.
I'm not able to reproduce this, but it looks worth fixing regardless.
We're fixing this on trunk though, and the output event looks different, and
there's one more output event:
...
{ "type": "event",
"event": "output",
"body": {
"category": "stdout",
"output": "No source file named log-message.c.\n"
},
"seq": 4
}
{ "type": "event",
"event": "output",
"body": {
"category": "stdout",
"output": "Breakpoint 1 (-source log-message.c -line 23) pending.\n"
},
"seq": 5
}
...
Fix this by waiting for these two output events, making the test-case a bit
more robust.
It is possible that one or both of these output events will be read by
dap_check_request_and_response "set breakpoint", and in that case restashing
them (for which there's currently no infrastructure) would be an easy way of
handling this. But I haven't been able to trigger that, so I'm leaving that
for if and when it does.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31831
Tom Tromey [Thu, 12 Jun 2025 16:48:25 +0000 (10:48 -0600)]
Allow DAP "threads" request when inferior is running
A user pointed out that DAP allows the "threads" request to work when
the inferior is running. This is documented in the overview, not the
specification.
While looking into this, I found a few other issues:
* The _thread_name function was not marked @in_gdb_thread.
This isn't very important but is still an oversight.
* DAP requires all threads to have a name -- the field is not optional
in the "Thread" type.
* There was no test examining events resulting from the inferior
printing to stdout.
Tom Tromey [Fri, 23 May 2025 23:48:30 +0000 (17:48 -0600)]
Use "MS" for .debug_str
I changed my system linker to 'mold', but then I saw some gdb test
failures. This patch fixes a subset of the failures.
dw2-strp.exp was failing, and investigating showed that there were two
.debug_str sections. I tracked this down to the .S file not using the
correct section flags.
This patch fixes this problem, plus the other instances I could find.
(Strangely, these did not all cause problems, however.) I also
changed the DWARF assembler to always use these flags for .debug_str.
Kito Cheng [Wed, 11 Jun 2025 08:33:49 +0000 (16:33 +0800)]
RISC-V: Support for unlabeled landing pad PLT generation
This patch adds support for generating unlabeled landing pad PLT entries
for the RISC-V architecture. Unlabeled landing pad will place a LPAD
instruction at the PLT entry and PLT header, also PLT header will have
few changes due to the offset is different from the original one.
Kito Cheng [Wed, 11 Jun 2025 08:33:46 +0000 (16:33 +0800)]
RISC-V: Refactor PLT generation
The goal of this refactor is to improve the possiblity of having
different PLT generation code for different RISC-V ABIs. The changes
include:
- Extract PLT generation logic into individual functions.
- Keep the PLT generation data in riscv_elf_link_hash_table.
In the following patches, we will use this framework to implement
different PLT.
Pawel Kupczak [Tue, 17 Jun 2025 14:08:15 +0000 (14:08 +0000)]
gdb: correct endbr64 instruction handling in amd64_analyze_prologue
Compilers can put a sequence aligning the stack at the entry of a
function. However with -fcf-protection enabled, "endbr64" is
generated before. Current implementation of amd64 prologue analyzer
first checks for stack alignment and then for "endbr64", which is not
correct. This behavior was introduced with patch "gdb: handle endbr64
instruction in amd64_analyze_prologue". In case both are generated,
prologue will not be skipped. This patch swaps the order so that
"endbr64" is checked first and adds a regression test. i386-tdep
implementation also already had those checked in the correct order,
that is stack alignment is after endbr64.
Given such source compiled with gcc 11.4.0 via:
gcc -O0 main.c -o main
int
main (int argc, char **argv)
{
foo (argc + 1);
return 1;
}
```
we get such function entry for foo (generated with objdump -d):
``` 0000000000001149 <foo>:
1149: f3 0f 1e fa endbr64
114d: 4c 8d 54 24 08 lea 0x8(%rsp),%r10
1152: 48 83 e4 c0 and $0xffffffffffffffc0,%rsp
1156: 41 ff 72 f8 push -0x8(%r10)
115a: 55 push %rbp
115b: 48 89 e5 mov %rsp,%rbp
115e: 41 52 push %r10
1160: 48 81 ec a8 00 00 00 sub $0xa8,%rsp
1167: 89 7d 8c mov %edi,-0x74(%rbp)
...
```
The 3 instructions following endbr64 align the stack. If we were to set
a breakpoint on foo, gdb would set it at function's entry:
```
(gdb) b foo
Breakpoint 1 at 0x1149
(gdb) r
...
Breakpoint 1, 0x0000555555555149 in foo ()
(gdb) disassemble
Dump of assembler code for function foo:
=> 0x0000555555555149 <+0>: endbr64
0x000055555555514d <+4>: lea 0x8(%rsp),%r10
0x0000555555555152 <+9>: and $0xffffffffffffffc0,%rsp
0x0000555555555156 <+13>: push -0x8(%r10)
0x000055555555515a <+17>: push %rbp
0x000055555555515b <+18>: mov %rsp,%rbp
0x000055555555515e <+21>: push %r10
0x0000555555555160 <+23>: sub $0xa8,%rsp
0x0000555555555167 <+30>: mov %edi,-0x74(%rbp)
...
```
With this patch fixing the order of checked instructions, gdb can
properly analyze the prologue:
```
(gdb) b foo
Breakpoint 1 at 0x115e
(gdb) r
...
Breakpoint 1, 0x000055555555515e in foo ()
(gdb) disassemble
Dump of assembler code for function foo:
0x0000555555555149 <+0>: endbr64
0x000055555555514d <+4>: lea 0x8(%rsp),%r10
0x0000555555555152 <+9>: and $0xffffffffffffffc0,%rsp
0x0000555555555156 <+13>: push -0x8(%r10)
0x000055555555515a <+17>: push %rbp
0x000055555555515b <+18>: mov %rsp,%rbp
=> 0x000055555555515e <+21>: push %r10
0x0000555555555160 <+23>: sub $0xa8,%rsp
0x0000555555555167 <+30>: mov %edi,-0x74(%rbp)
...
```
Pawel Kupczak [Tue, 17 Jun 2025 14:08:14 +0000 (14:08 +0000)]
gdb: refactor amd64_analyze_prologue
Refactor amd64_analyze_prologue so it clearly reflects what is the order
of operations in the prologue that we expect to encounter, as is the
case for i386's implementation.
Andrew Burgess [Tue, 3 Jun 2025 13:26:50 +0000 (14:26 +0100)]
gdb/testsuite: use TESTS from make-check-all.sh
Update the make-check-all.sh script to use TESTS rather than passing
the test names within RUNTESTFLAGS. This addresses the following
issue:
I was running some tests like this:
make -C gdb check-all-boards TESTS="gdb.base/break*.exp"
And I was finding that I would get lots of DUPLICATE test results,
which is not what I expected.
What's happening here is that the 'make check-all-boards' rule runs
the 'make-check-all.sh' script, which then runs 'make check' with
various board files.
However, passing TESTS=... to the initial 'make check-all-boards'
command invocation automatically causes the TESTS value to be added to
the MAKEFLAGS environment variable, this is then picked up by the
later calls to 'make check'.
Now, in GDB's testfile/Makefile, we check for TESTS, and if this is
set, we expand the value and set `expanded_tests_or_none`. Otherwise,
if TESTS is not set, expanded_tests_or_none is left empty.
Finally, when handling 'make check', the value of
`expanded_tests_or_none` is passed through to dejagnu, along with the
RUNTESTFLAGS value.
What this means is that, when make-check-all.sh passes the test names
in the RUNTESTFLAGS, then dejagnu ends up seeing the list of tests
twice, once from RUNTESTFLAGS, and once from expanded_tests_or_none,
and this is why I was seeing duplicate testnames.
The easiest fix for the above is to have make-check-all.sh pass the
test names using TESTS="...", this will override the TESTS="..." value
already present in MAKEFLAGS, and means dejagnu will see the test
names just once.
Additionally, this is a start towards allowing parallel test running
from the make-check-all.sh script. Parallel test running only works
if the test names are passed in TESTS, and not in RUNTESTFLAGS.
Currently, in testsuite/Makefile, if RUNTESTFLAGS is not empty, then
we force single threaded test running. But with this change, at least
for the `local` board, we can now benefit from multi-threaded test
running, as this board has an empty RUNTESTFLAGS now. For the other
boards we'd need to set FORCE_PARALLEL in order to benefit from
parallel test running, but we'll need to double check that all the
board files actually support parallel test running first, so I'm
leaving that for another day.
gdb: use quoted filename completion for the shell command
which fixed the completion for the 'shell' command itself.
Like with the 'shell' command, we don't offer completions of command
names pulled from $PATH, we just offer filename completion, which is
often useful for arguments being passed to commands. Maybe in the
future we could add completion for command names too (for both 'pipe'
and the 'shell' command), but that is left for a future commit.
Benjamin Berg [Tue, 21 Mar 2023 12:01:26 +0000 (13:01 +0100)]
gdb: linux-namespaces: enter user namespace when appropriate
The use of user namespaces is required for normal users to use mount
namespaces. Consider trying this as an unprivileged user:
$ unshare --mount /bin/true
unshare: unshare failed: Operation not permitted
The problem here is that an unprivileged user doesn't have the
required permissions to create a new mount namespace. If, instead, we
do this:
$ unshare --mount --map-root-user /bin/true
then this will succeed. The new option causes unshare to create a
user namespace in which the unprivileged user is mapped to UID/GID 0,
and so gains all privileges (inside the namespace), the user is then
able to create the mount namespace as required.
So, how does this relate to GDB?
When a user attaches to a process running in a separate mount
namespace, GDB makes use of a separate helper process (see
linux_mntns_get_helper in nat/linux-namespaces.c), which will then use
the `setns` function to enter (or try to enter) the mount namespace of
the process GDB is attaching too. The helper process will then handle
file I/O requests received from GDB, and return the results back to
GDB, this allows GDB to access files within the mount namespace.
The problem here is that, switching to a mount namespace requires that
a process hold CAP_SYS_CHROOT and CAP_SYS_ADMIN capabilities within
its user namespace (actually it's a little more complex, see 'man 2
setns'). Assuming GDB is running as an unprivileged user, then GDB
will not have the required permissions.
However, if GDB enters the user namespace that the `unshare` process
created, then the current user will be mapped to UID/GID 0, and will
have the required permissions.
And so, this patch extends linux_mntns_access_fs (in
nat/linux-namespace.c) to first try and switch to the user namespace
of the inferior before trying to switch to the mount namespace. If
the inferior does have a user namespace, and does have elevated
privileges within that namespace, then this first switch by GDB will
mean that the second step, into the mount namespace, will succeed.
If there is no user namespace, or the inferior doesn't have elevated
privileges within the user namespace, then the switch into the mount
namespace will fail, just as it currently does, and the user will need
to give elevated privileges to GDB via some other mechanism (e.g. run
as root).
I (Andrew Burgess) have made some cleanups to the code to comply with
GDB's coding standard, and the test is entirely mine. This commit
message is also entirely mine -- the original message was very terse
and required the reader to understand how the various namespaces
work and interact. The above is my attempt to document what I now
understand about the problem being fixed.
I've left the original author in place as the core of the GDB change
itself is largely as originally presented, but any inaccuracies in the
commit message, or problems with the test, are all mine.
Co-Authored-by: Andrew Burgess <aburgess@redhat.com>
gdb: attach to a process when the executable has been deleted
The above commit extended GDB for Linux, so that, of the executable
for a process had been deleted, GDB would instead try to use
/proc/PID/exe as the executable.
This worked by updating linux_proc_pid_to_exec_file to introduce the
/proc/PID/exe fallback. However, the result of
linux_proc_pid_to_exec_file is then passed to exec_file_find to
actually find the executable, and exec_file_find, will take into
account the sysroot. In addition, if GDB is attaching to a process in
a different MNT and/or PID namespace then the executable lookup is
done within that namespace.
This all means two things:
1. Just because linux_proc_pid_to_exec_file cannot see the
executable doesn't mean that GDB is actually going to fail to
find the executable, and
2. returning /proc/PID/exe isn't useful if we know GDB is then going
to look for this within a sysroot, or within some other
namespace (where PIDs might be different).
There was an initial attempt to fix this issue here:
This proposal addresses the issue in PR gdb/32955, which is all about
the namespace side of the problem. The fix in this original proposal
is to check the MNT namespace inside linux_proc_pid_to_exec_file, and
for the namespace problem this is fine. But we should also consider
the sysroot problem.
And for the sysroot problem, the fix cannot fully live inside
linux_proc_pid_to_exec_file, as linux_proc_pid_to_exec_file is shared
between GDB and gdbserver, and gdbserver has no sysroot.
And so, I propose a slightly bigger change.
Now, linux_proc_pid_to_exec_file takes a flag which indicates if
GDB (or gdbserver) will look for the inferior executable in the
local file system, where local means the same file system as GDB (or
gdbserver) is running in.
This local file system check is true if:
1. The MNT namespace of the inferior is the same as for GDB, and
2. for GDB only, the sysroot must either be empty, or 'target:'.
If the local file system check is false then GDB (or gdbserver) is
going to look elsewhere for the inferior executable, and so, falling
back to /proc/PID/exe should not be done, as GDB will end up looking
for this file in the sysroot, or within the alternative MNT
namespace (which in also likely to be a different PID namespace).
Now this is all a bit of a shame really. It would be nice if
linux_proc_pid_to_exec_file could return /proc/PID/exe in such a way
that exec_file_find would know that the file should NOT be looked for
in the sysroot, or in the alternative namespace. But fixing that
problem would be a much bigger change, so for now lets just disable
the /proc/PID/exe fallback for cases where it might not work.
For testing, the sysroot case is now tested.
I don't believe we have any alternative namespace testing. It would
certainly be interesting to add some, but I'm not proposing any with
this patch, so the code for checking the MNT namespace has been tested
manually by me, but isn't covered by a new test I'm adding here.
Author of the original fix is listed as co-author here. Credit for
identifying the original problem, and proposing a solution belongs to
them.
Andrew Burgess [Thu, 22 May 2025 13:29:49 +0000 (14:29 +0100)]
gdb: better warning when attaching, and executable is unknown
Currently, when attaching to a process, if the user hasn't told GDB
which executable they are going to be debugging, GDB will try to
figure out the executable from the running process.
There are two (for this patch) interesting places where this can fail,
both in exec_file_locate_attach.
First GDB calls target_pid_to_exec_file, this does target specific
"stuff" to find the name of the executable file. If this returns NULL
then GDB will give a warning and return.
After this we need to "find" the executable. This is where we apply
things like the sysroot in order to transform the executable path.
This is done by calling exec_file_find, and this too can return NULL
to indicate that the executable couldn't be found.
Currently, if exec_file_find returns NULL then GDB doesn't give a
warning, instead we push on and call try_open_exec_file passing in the
NULL pointer as the filename string. This has the effect of removing
the current executable from the current program space.
However, exec_file_locate_attach already checks there is no executable
attached to the current program space. If there was, then there would
be no need to try and lookup the executable from the running process.
So calling try_open_exec_file with a NULL string is, I claim,
pointless.
But worse, calling try_open_exec_file with a NULL string means that
GDB prints the message: "No executable file now.", which, while
correct, isn't (I think) very helpful. To me this message indicates
that we've moved from a state of having an executable to a state of
not having one, which isn't correct.
I think we should introduce a new warning in exec_file_locate_attach,
which is printed if the executable cannot be found.
So, before this patch GDB's output looked like this:
(gdb) attach 12345
Attaching to process 12345
No executable file now.
warning: Could not load vsyscall page because no executable was specified
0x00007f0978b94557 in ?? ()
(gdb)
After this patch the output now looks like this:
(gdb) attach 12345
Attaching to process 12345
No executable has been specified, and target executable /tmp/my-exec (deleted) could not be found. Try using the "file" command.
warning: Could not load vsyscall page because no executable was specified
0x00007f0978b94557 in ?? ()
(gdb)
This warning includes the name of the file that GDB was looking for,
and gives a hint that the 'file' command should be used to tell GDB
which executable is being debugged. Much better.
There's no test for this change in this commit. The next commit fixes
another (semi-related) bug, and includes a test that checks for this
warning string.
gdb: implement linux namespace support for fileio_lstat and vFile::lstat
The build failure looks like this:
../../src/gdbserver/hostio.cc: In function 'void handle_lstat(char*, int*)':
../../src/gdbserver/hostio.cc:544:63: error: cannot convert '_stat64*' to 'stat*'
544 | ret = the_target->multifs_lstat (hostio_fs_pid, filename, &st);
| ^~~
| |
| _stat64*
In file included from ./../../src/gdbserver/server.h:58,
from <command-line>:
./../../src/gdbserver/target.h:448:74: note: initializing argument 3 of 'virtual int process_stratum_target::multifs_lstat(int, const char*, stat*)'
448 | virtual int multifs_lstat (int pid, const char *filename, struct stat *sb);
| ~~~~~~~~~~~~~^~
The problem is that in sys/stat.h for mingw, 'stat' is #defined to
_stat64, but target.h doesn't include sys/stat.h, and so doesn't see
this #define.
However, target.h does, by luck, manages to see the actual definition
of 'struct stat', which isn't in sys/stat.h itself, but is in some
other header that just happens to be pulled in by chance.
As a result of all this, the declaration of
process_stratum_target::multifs_lstat in target.h uses 'struct stat'
for its argument type, while the call in hostio.cc, uses 'struct
_stat64' as its argument type, which causes the build error seen
above.
The fix is to include sys/stat.h in target.h so that the declaration's
argument type will change to 'struct _stat64' (via the #define).
Stafford Horne [Sun, 15 Jun 2025 04:15:40 +0000 (05:15 +0100)]
or1k: Fix disassembly for little-endian binaries
There are some OpenRISC CPUs that have their binaries stored in
little-endian format. Using objdump to disassemble these is
problematic, as some instructions fail to disassemble, for example:
It was found that the hash function was using the still little-endian
buffer to extract the opcode used for the hash lookup. This didn't work
as it was pulling the wrong hashcode causing instruction lookup to fail.
Fix the hash function by using the normalized/byte-swapped value instead
of the buffer.
aarch64: Support 2024 Debug Architecture system registers.
This patch adds support for following system registers and the spec
can be found here[1].
1. PMBSR_EL12, PMBSR_EL2, PMBSR_EL3, PMBMAR_EL1 depends on FEAT_SPE
and Armv9.5-A architecture and these are enabled by passing
-march=armv9.5-a+profile.
2. TRBSR_EL12, TRBSR_EL2, and TRBSR_EL3 depends Armv9.5-A architecture
and these are enabled by passing -march=armv9.5-a.
3. HFGITR2_EL2 depends on Armv8.8-A architecture and enabled by passing
-march=armv8.8-a.
Kirill Radkin [Tue, 3 Jun 2025 13:48:23 +0000 (16:48 +0300)]
gdbserver: Update require_int function to parse offset for pread packet
Currently gdbserver uses the require_int() function to parse the
requested offset (in vFile::pread packet and the like). This function
allows integers up to 0x7fffffff (to fit in 32-bit int), however the
offset (for the pread system call) has an off_t type which can be
larger than 32-bit.
This patch allows require_int() function to parse offset up to the
maximum value implied by the off_t type.
Approved-By: Pedro Alves <pedro@palves.net>
Change-Id: I3691bcc1ab1838c0db7f8b82d297d276a5419c8c
Ezra Sitorus [Thu, 5 Jun 2025 14:27:15 +0000 (15:27 +0100)]
aarch64: Add occmo flag for FEAT_OCCMO
FEAT_OCCMO support was introduced, but the feature flags were missing.
This patch adds these flags, as well as splitting up the tests to test
occmo vs occmo+memtag operands.
Ezra Sitorus [Thu, 19 Jun 2025 09:40:43 +0000 (10:40 +0100)]
aarch64: Support for FEAT_SVE_BFSCALE
FEAT_SVE_BFSCALE introduces the SVE BFSCALE instruction, when the PE is not in
Streaming SVE mode. If FEAT_SME2 is implemented, FEAT_SVE_BFSCALE also
introduces SME multi-vector Z-targeting BFloat16 scaling instructions, BFSCALE
and BFMUL.
Andrew Burgess [Thu, 12 Jun 2025 13:29:16 +0000 (14:29 +0100)]
gdb/python: introduce gdb.warning() function
This commit adds a new gdb.warning() function. This function takes a
string and then calls GDB's internal warning() function. This will
display the string as a warning.
Using gdb.warning() means that the message will get the new emoji
prefix if the user has that feature turned on. Also, the message will
be sent to gdb.STDERR without the user having to remember to print to
the correct stream.
Reviewed-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Tom Tromey <tom@tromey.com>
WANG Xuerui [Tue, 17 Jun 2025 08:12:02 +0000 (16:12 +0800)]
LoongArch: Batch-delete bytes at the end of each relax trip
Previously, memmove and reloc/symbol adjustments happened at each
loongarch_relax_delete_bytes() call, which is O(n^2) time complexity and
leads to unacceptable (multiple hours) linking times for certain inputs
with huge number of relaxable sites -- see the linked issue for details.
To get rid of the quadratic behavior, defer all delete ops to the end of
each relax trip, with the buffer implemented with the splay tree from
libiberty. The individual relaxation handlers are converted to handle
symbol values and relocation offsets as if all preceding deletions
actually happened, by querying a cumulative offset from the splay tree;
the accesses should be efficient because they are mostly sequential
during a relaxation trip. The exact relaxation behavior remains largely
unchanged.
Example running times before and after the change with the test case in
the linked issue (mypy transpiled C), cross-linking on Threadripper
3990X:
Before: 4192.80s user 1.09s system 98% cpu 1:10:53.52 total
After: 1.76s user 0.74s system 98% cpu 2.539 total - ~1/2382 the time!
Also tested with binutils (bootstrapping self), CPython 3.14 and LLVM
20.1.6; all passed the respective test suites.
Fabian Kilger [Wed, 11 Jun 2025 20:52:17 +0000 (22:52 +0200)]
gdb: query inferior's filesystem for build-id debug files
This fixes a bug related to build-id files with linux namespaces.
Specifically, we expect the debug files to be present inside the container,
thus the container filesystem should be queried if the program is running
inside one.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32956 Approved-By: Andrew Burgess <aburgess@redhat.com>
Fabian Kilger [Wed, 11 Jun 2025 20:52:16 +0000 (22:52 +0200)]
gdb: implement linux namespace support for fileio_lstat and vFile::lstat
The new algorithm to look for a build-id-based debug file
(introduced by commit 22836ca88591ac7efacf06d5b6db191763fd8aba)
makes use of fileio_lstat. As lstat was not supported by
linux-namespace.c, all lstat calls would be performed on the host
and not inside the namespace. Fixed by adding namespace lstat
support.
Andrew Burgess [Wed, 11 Jun 2025 14:04:38 +0000 (15:04 +0100)]
gdbserver: fix vFile:stat to actually use 'stat'
This commit continues the work of the previous two commits.
In the following commits I added the target_fileio_stat function, and
the target_ops::fileio_stat member function:
* 08a115cc1c4 gdb: add target_fileio_stat, but no implementations yet
* 3055e3d2f13 gdb: add GDB side target_ops::fileio_stat implementation
* 6d45af96ea5 gdbserver: add gdbserver support for vFile::stat packet
* 22836ca8859 gdb: check for multiple matching build-id files
Unfortunately I messed up, despite being called 'stat' these function
actually performed an 'lstat'. The 'lstat' is the correct (required)
implementation, it's the naming that is wrong.
Additionally, to support remote targets, these commit added the
vFile::stat packet, which again, performed an 'lstat'.
In the previous two commits I changed the GDB code to replace 'stat'
with 'lstat' in the fileio function names. I then added a new
vFile:lstat packet which GDB now uses instead of vFile:stat.
And that just leaves the vFile:stat packet which is, right now,
performing an 'lstat'.
Now, clearly when I wrote this code I fully intended for this packet
to perform an lstat, it's the lstat that I needed. But now, I think,
we should "fix" vFile:stat to actually perform a 'stat'.
This is risky. This is a change in remote protocol behaviour.
Reasons why this might be OK:
- vFile:stat was only added in GDB 16, so it's not been "in the
wild" for too long yet. If we're quick, we might be able to "fix"
this before anyone realises I messed up.
- The documentation for vFile:stat is pretty vague. It certainly
doesn't explicitly say "this does an lstat". Most implementers
would (I think), given the name, start by assuming this should be
a 'stat' (given the name). Only if they ran the full GDB
testsuite, or examined GDB's implementation, would they know to
use lstat.
Reasons why this might not be OK:
- Some other debug client could be connecting to gdbserver, sending
vFile:stat and expecting to get lstat behaviour. This would break
after this patch.
- Some other remote server might have implemented vFile:stat
support, and either figured out, or copied, the lstat behaviour
from gdbserver. This remote server would technically be wrong
after this commit, but as GDB no longer uses vFile:stat, then this
will only become a problem if/when GDB or some other client starts
to use vFile:stat in the future.
Given the vague documentation for vFile:stat, and that it was only
added in GDB 16, I think we should fix it now to perform a 'stat', and
that is what this commit does.
The change in behaviour is documented in the NEWS file. I've improved
the vFile:stat documentation in the manual to better explain what is
expected from this packet, and I've extended the existing test to
cover vFile:stat.
Reviewed-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Tom Tromey <tom@tromey.com>
Andrew Burgess [Wed, 11 Jun 2025 19:01:56 +0000 (20:01 +0100)]
gdbserver: add vFile:lstat packet support
In the following commits I added the target_fileio_stat function, and
the target_ops::fileio_stat member function:
* 08a115cc1c4 gdb: add target_fileio_stat, but no implementations yet
* 3055e3d2f13 gdb: add GDB side target_ops::fileio_stat implementation
* 6d45af96ea5 gdbserver: add gdbserver support for vFile::stat packet
* 22836ca8859 gdb: check for multiple matching build-id files
Unfortunately I messed up, despite being called 'stat' these function
actually performed an 'lstat'. The 'lstat' is the correct (required)
implementation, it's the naming that is wrong.
In the previous commit I fixed the naming within GDB, renaming 'stat'
to 'lstat' throughout.
However, in order to support target_fileio_stat (as was) on remote
targets, the above patches added the vFile:stat packet, which actually
performed an 'lstat' call. This is really quite unfortunate, and I'd
like to do as much as I can to try and clean up this mess. But I'm
mindful that changing packets is not really the done thing.
So, this commit doesn't change anything.
Instead, this commit adds vFile:lstat as a new packet.
Currently, this packet is handled identically as vFile:stat, the
packet performs an 'lstat' call.
I then update GDB to send the new vFile:lstat instead of vFile:stat
for the remote_target::fileio_lstat implementation.
After this commit GDB will never send the vFile:stat packet.
However, I have retained the 'set remote hostio-stat-packet' control
flag, just in case someone was trying to set this somewhere.
Then there's one test in the testsuite which used to disable the
vFile:stat packet, that test is updated to now disable vFile:lstat.
There's a new test that does a more direct test of vFile:lstat. This
new test can be extended to also test vFile:stat, but that is left for
the next commit.
And so, after this commit, GDB sends the new vFile:lstat packet in
order to implement target_ops::fileio_lstat. The new packet is more
clearly documented than vFile:stat is. But critically, this change
doesn't risk breaking any other clients or servers that implement
GDB's remote protocol.
Reviewed-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Tom Tromey <tom@tromey.com>
Andrew Burgess [Wed, 11 Jun 2025 15:10:26 +0000 (16:10 +0100)]
gdb: rename target_fileio_stat to target_fileio_lstat
In the following commits I added the target_fileio_stat function, and
the target_ops::fileio_stat member function:
* 08a115cc1c4 gdb: add target_fileio_stat, but no implementations yet
* 3055e3d2f13 gdb: add GDB side target_ops::fileio_stat implementation
* 6d45af96ea5 gdbserver: add gdbserver support for vFile::stat packet
* 22836ca8859 gdb: check for multiple matching build-id files
Unfortunately, I messed up when adding this API. The actual
underlying call is lstat, not stat.
This commit tries to clear up some of the confusion by renaming things
to target_fileio_lstat and target_ops::fileio_lstat.
After this change the function names now match the underlying
implementation.
One problem remains though. In order to support target_fileio_stat
for remote target the above patches added the vFile:stat packet to GDB
and gdbserver. The implementation of this packet still does an lstat
though, which is a bit of a shame. I'm going to try and fix that in
later commits.
This commit is just a rename within GDB, there should be no user
visible changes.
Timur [Mon, 26 May 2025 12:43:16 +0000 (15:43 +0300)]
gdb/record: Support csrrci instruction in risc-v
During testing csr instructions in risc-v, it occurs that instruction csrrci
is unsupported for recording process and there is such warning:
'warning: Currently this instruction with len 4(100174f3) is unsupported', so
recording failed. This patch fixes this error.
Tom de Vries [Tue, 17 Jun 2025 06:28:50 +0000 (08:28 +0200)]
[gdb/testsuite] Set interactive-mode to on
With MSYS2 and test-case gdb.ada/assign_1.exp, we get:
...
(gdb) dir^M
Reinitialize source path to empty? (y or n) \
[answered Y; input not from terminal]^M^M
Source directories searched: $cdir;$cwd^M^M
(gdb)
...
GDB automatically answers the query, because interactive-mode is off:
...
(gdb) show interactive-mode^M
Debugger's interactive mode is auto (currently off).^M^M
...
The correct value is on, because GDB was started in a terminal.
For some reason, the auto value of interactive-mode is off instead. According
to this patch [1], gdb doesn't recognize the pipes used by DejaGnu testsuite
as an interactive setup.
Fix this by adding "set interactive-mode on" to INTERNAL_GDBFLAGS, such that
we get:
...
(gdb) dir^M
Reinitialize source path to empty? (y or n) y^M
Source directories searched: $cdir;$cwd^M^M
(gdb)
...
and no longer need fixes like commit be740e7cc62 ("testsuite: skip
confirmation in 'gdb_reinitialize_dir'")
The fix is essentially the same as in aforementioned patch.
For consistency, we apply the fix for all platforms.
Co-Authored-By: Pierre Muller <muller@sourceware.org> Approved-By: Tom Tromey <tom@tromey.com>
[1] https://sourceware.org/legacy-ml/gdb-patches/2013-09/msg00940.html
Tom de Vries [Tue, 17 Jun 2025 06:28:50 +0000 (08:28 +0200)]
[gdb/testsuite] Set TERM to dumb by default
With MSYS2 and default TERM=xterm-256color (as well as with xterm and ansi), I
get:
...
builtin_spawn gdb -q ...
^[[6n(gdb) ERROR: GDB never initialized.
...
This is not specific to gdb, other tools produce the same CSI sequence, and
consequently we run into trouble in other places (like get_compiler_info).
Fix this by default-setting TERM to dumb.
We do this for all platforms, to avoid test-cases passing on one platform but
failing on another.
For test-cases that set TERM to something other than dumb, handle the CSI
sequence in default_gdb_start.
Approved-By: Tom Tromey <tom@tromey.com>
PR testsuite/33072
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33072
Recent GDB commits added more features related to linker namespaces and
documented them on the manual, but did not add a convenient way for a
user to understand what they are. This commit adds a quick explanation
of what they are.
It also fixes the inconsistency of using "linker namespaces" and
"linkage namespaces", by always using the first form to avoid user
confusion.
- A kernel is launched
- The internal runtime breakpoint is hit during the second
hipLaunchKernelGGL call, which causes
amd_dbgapi_target_breakpoint::check_status to be called
- Meanwhile, all waves of the kernel hit the breakpoint on vectorADD
- amd_dbgapi_target_breakpoint::check_status calls process_event_queue,
which pulls the thousand of breakpoint hit events from the kernel
- As part of handling the breakpoint hit events, we write the PC of the
waves that stopped to decrement it. Because the forward progress
requirement is not disabled, this causes a suspend/resume of the
queue each time, which is time-consuming.
The stack trace where this all happens is:
#32 0x00007ffff6b9abda in amd_dbgapi_write_register (wave_id=..., register_id=..., offset=0, value_size=8, value=0x7fffea9fdcc0) at /home/smarchi/src/amd-dbgapi/src/register.cpp:587
#33 0x00005555588c0bed in amd_dbgapi_target::store_registers (this=0x55555c7b1d20 <the_amd_dbgapi_target>, regcache=0x507000002240, regno=470) at /home/smarchi/src/wt/amd/gdb/amd-dbgapi-target.c:2504
#34 0x000055555a5186a1 in target_store_registers (regcache=0x507000002240, regno=470) at /home/smarchi/src/wt/amd/gdb/target.c:3973
#35 0x0000555559fab831 in regcache::raw_write (this=0x507000002240, regnum=470, src=...) at /home/smarchi/src/wt/amd/gdb/regcache.c:890
#36 0x0000555559fabd2b in regcache::cooked_write (this=0x507000002240, regnum=470, src=...) at /home/smarchi/src/wt/amd/gdb/regcache.c:915
#37 0x0000555559fc3ca5 in regcache::cooked_write<unsigned long, void> (this=0x507000002240, regnum=470, val=140737323456768) at /home/smarchi/src/wt/amd/gdb/regcache.c:850
#38 0x0000555559fab09a in regcache_cooked_write_unsigned (regcache=0x507000002240, regnum=470, val=140737323456768) at /home/smarchi/src/wt/amd/gdb/regcache.c:858
#39 0x0000555559fb0678 in regcache_write_pc (regcache=0x507000002240, pc=0x7ffff62bd900) at /home/smarchi/src/wt/amd/gdb/regcache.c:1460
#40 0x00005555588bb37d in process_one_event (event_id=..., event_kind=AMD_DBGAPI_EVENT_KIND_WAVE_STOP) at /home/smarchi/src/wt/amd/gdb/amd-dbgapi-target.c:1873
#41 0x00005555588bbf7b in process_event_queue (process_id=..., until_event_kind=AMD_DBGAPI_EVENT_KIND_BREAKPOINT_RESUME) at /home/smarchi/src/wt/amd/gdb/amd-dbgapi-target.c:2006
#42 0x00005555588b1aca in amd_dbgapi_target_breakpoint::check_status (this=0x511000140900, bs=0x50600014ed00) at /home/smarchi/src/wt/amd/gdb/amd-dbgapi-target.c:890
#43 0x0000555558c50080 in bpstat_stop_status (aspace=0x5070000061b0, bp_addr=0x7fffed0b9ab0, thread=0x518000026c80, ws=..., stop_chain=0x50600014ed00) at /home/smarchi/src/wt/amd/gdb/breakpoint.c:6126
#44 0x000055555984f4ff in handle_signal_stop (ecs=0x7fffeaa40ef0) at /home/smarchi/src/wt/amd/gdb/infrun.c:7169
#45 0x000055555984b889 in handle_inferior_event (ecs=0x7fffeaa40ef0) at /home/smarchi/src/wt/amd/gdb/infrun.c:6621
#46 0x000055555983eab6 in fetch_inferior_event () at /home/smarchi/src/wt/amd/gdb/infrun.c:4750
#47 0x00005555597caa5f in inferior_event_handler (event_type=INF_REG_EVENT) at /home/smarchi/src/wt/amd/gdb/inf-loop.c:42
#48 0x00005555588b838e in handle_target_event (client_data=0x0) at /home/smarchi/src/wt/amd/gdb/amd-dbgapi-target.c:1513
Fix that performance problem by disabling the forward progress
requirement in amd_dbgapi_target_breakpoint::check_status, before
calling process_event_queue, so that we can process all events
efficiently.
Since the same performance problem could theoritically happen any time
process_event_queue is called with forward progress requirement enabled,
add an assert to ensure that forward progress requirement is disabled
when process_event_queue is invoked. This makes it necessary to add a
require_forward_progress call to amd_dbgapi_finalize_core_attach. It
looks a bit strange, since core files don't have execution, but it
doesn't hurt.
Add a test that replicates this scenario. The test launches a kernel
that hits a breakpoint (with an always false condition) repeatedly.
Meanwhile, the host process loads an unloads a code object, causing
check_status to be called.
Bug: SWDEV-482511
Change-Id: Ida86340d679e6bd8462712953458c07ba3fd49ec Approved-by: Lancelot Six <lancelot.six@amd.com>
Simon Marchi [Mon, 9 Jun 2025 16:09:01 +0000 (12:09 -0400)]
gdb/amd-dbgapi: factor out require_forward_progress overload to target one inferior
A following patch will want to call require_forward_progress for a given
inferior. Extract a new require_forward_progress overload from the
existing require_forward_progress function that targets a specific
inferior.
Change-Id: I54f42b83eb8443d4d91747ffbc86eaeb017f1e49 Approved-by: Lancelot Six <lancelot.six@amd.com>
Simon Marchi [Mon, 9 Jun 2025 16:09:00 +0000 (12:09 -0400)]
gdb/amd-dbgapi: pass amd_dbgapi_inferior_info to process_one_event
Pass the amd_dbgapi_inferior_info object from process_event_queue to
process_one_event. Since process_event_queue pulls events for one
specific inferior, we know for which inferior the event is. This
removes the need for process_one_event to do two dbgapi calls to get the
relevant pid. If also removes one inferior lookup.
Change-Id: I22927e4b6251513eb3be95785082058aa3d09954 Approved-by: Lancelot Six <lancelot.six@amd.com>
Simon Marchi [Mon, 9 Jun 2025 16:08:59 +0000 (12:08 -0400)]
gdb/amd-dbgapi: pass amd_dbgapi_inferior_info to process_event_queue
A following patch will make process_event_queue access a field of
amd_dbgapi_inferior_info. Prepare for this by making
process_event_queue accept an amd_dbgapi_inferior_info object, instead
of a process id.
Change-Id: I9adc491dd1ff64ff74c40aa7662fffb11bd8332b Approved-by: Lancelot Six <lancelot.six@amd.com>
Simon Marchi [Mon, 9 Jun 2025 16:08:58 +0000 (12:08 -0400)]
gdb/amd-dbgapi: add assert in require_forward_progress
I didn't have a problem in this area, but it seems to me that this
pre-condition should always hold. We should only disable forward
progress requirement if the target says it's ok to do so. Otherwise, we
could get in a situation where we wait for events from amd-dbgapi, which
will never arrive, because amd-dbgapi didn't actually resume things.
Change-Id: Ifc49f55c7874924b7c47888b8391a07a01d960fc Approved-by: Lancelot Six <lancelot.six@amd.com>
Tom de Vries [Mon, 16 Jun 2025 13:13:25 +0000 (15:13 +0200)]
[gdb/testsuite] Fix gdb.python/py-source-styling-2.exp with TERM=dumb
When running test-case gdb.python/py-source-styling-2.exp with TERM=dumb, I
get:
...
(gdb) set style enabled on^M
warning: The current terminal doesn't support styling. \
Styled output might not appear as expected.^M
(gdb) FAIL: $exp: set style enabled on
...
Fix this by using with_ansi_styling_terminal on clean_restart.
+#if BFD_SUPPORTS_PLUGINS
+ /* Copy LTO IR file as unknown object. */
+ if (bfd_plugin_target_p (ibfd->xvec))
^^^^ A typo, should be this_element.
+ ok_object = false;
+ else
+#endif
if (ok_object)
{
ok = copy_object (this_element, output_element, input_arch);
to check if the archive element is a LTO IR file. "ibfd" is the archive
BFD. "this_element" should be used to check for LTO IR in the archive
element. Fix it by replacing "ibfd" with "this_element".
PR binutils/33078
* objcopy.c (copy_archive): Correctly check archive element for
LTO IR.
* testsuite/binutils-all/objcopy.exp (strip_test_archive): New.
Run strip_test_archive.
Stafford Horne [Sun, 1 Jun 2025 05:39:01 +0000 (06:39 +0100)]
or1k: Add support for numcores and coreid sprs
These are needed when running GCC tests for newlib toolchains built with
multicore support. Without these SPRs we get the following warnings
when running tests.
spawn or1k-elf-run ./20000112-1.exe^M
WARNING: l.mfspr with invalid SPR address 0x80^M
WARNING: l.mfspr with invalid SPR address 0x81^M
WARNING: l.mfspr with invalid SPR address 0x81^M
WARNING: l.mfspr with invalid SPR address 0x81^M
Support is added by defining the SPRs in the cgen machine definition and
regenerating the machine code. In or1k/or1k.c we initialize NUMCORES to
1 and COREID to 0 as the sim has only one CPU. In or1k/traps.c we allow
returning the NUMCORES and COREID spr values in the mfspr function.
Simon Marchi [Mon, 5 May 2025 20:15:26 +0000 (16:15 -0400)]
gdbsupport: make gdb::parallel_for_each's n parameter a template parameter
This value will likely never change at runtime, so we might as well make
it a template parameter. This has the "advantage" of being able to
remove the unnecessary param from gdb::sequential_for_each.
Change-Id: Ia172ab8e08964e30d4e3378a95ccfa782abce674 Approved-By: Tom Tromey <tom@tromey.com>
Simon Marchi [Fri, 2 May 2025 17:57:57 +0000 (13:57 -0400)]
gdb: re-work parallel-for-selftests.c
I find this file difficult to work with and modify, due to how it uses
the preprocessor to include itself, to generate variations of the test
functions. Change it to something a bit more C++-y, with a test
function that accepts a callback to invoke the foreach function under
test.
Jan Beulich [Fri, 13 Jun 2025 11:46:30 +0000 (13:46 +0200)]
x86: don't constrain %axl/%cxl
They can be used like their %al/%cl counterparts everywhere else;
there's no apparent reason why they shouldn't be usable as accumulator /
shift count respectively. Enforcing such a restriction only makes
writing heavily macro-ized code more cumbersome.
Jan Beulich [Fri, 13 Jun 2025 11:46:06 +0000 (13:46 +0200)]
x86: swap operands in OUT-with-immediate template
In a number of places we assume that immediates come first in the set of
operands. It is mere luck that so far OUT, having operands the other way
around, wasn't negatively impacted by this.
Leverage this to have a few loops start from the first non-immediate
operand (or in one case to stop there). Note, however, that
process_immext() inserts an immediate last, so especially all output_*()
functions cannot be changed in the same way.
objcopy: /tmp/objcopy-poc(OrcError.cpp.o): invalid entry (0x22000000) in group [3]
objcopy: /tmp/objcopy-poc(OrcError.cpp.o): invalid entry (0x21000000) in group [3]
objcopy: /tmp/objcopy-poc(OrcError.cpp.o)(.text._ZNK12_GLOBAL__N_116OrcErrorCategory7messageB5cxx11Ei): relocation 29 has invalid symbol index 1160982879
objcopy: /tmp/stv73zYw/OrcError.cpp.o[.text._ZN4llvm3orc8orcErrorENS0_12OrcErrorCodeE]: bad value
instead of
objcopy: /tmp/objcopy-poc(OrcError.cpp.o): invalid entry (0x22000000) in group [3]
objcopy: /tmp/objcopy-poc(OrcError.cpp.o): invalid entry (0x21000000) in group [3]
objcopy: /tmp/objcopy-poc(OrcError.cpp.o)(.text._ZNK12_GLOBAL__N_116OrcErrorCategory7messageB5cxx11Ei): relocation 29 has invalid symbol index 1160982879
Segmentation fault (core dumped)
PR binutils/33075
* elf.c (elf_map_symbols): Return false if output_section is
NULL.
Jan Beulich [Fri, 13 Jun 2025 06:40:32 +0000 (08:40 +0200)]
x86: refine UD<n> kind-of-insns
While documentation of these continues to be lacking sufficient detail,
it is becoming increasingly clear that in 66f1eba0b7e8 ("x86: correct
UDn") I went too far with requiring operands, to populate a ModR/M byte.
AMD hardware appears to always behave as indicated as "may" in PM 3.36,
which for all practical purposes means there's no ModR/M byte. The SDM
(rev 087) indicates that such behavior can occur on older hardware for
UD0. Re-add an operand-less UD1 form (as well as its UD2B alias), while
newly adding such a form also for UD0. Because of the ambiguity, there's
no good/easy way of handling both possibilities in the disassembler,
which hence remains unaltered.
Further, from all information I'm able to gather, the 0F opcode space
was only introduced with the i286; bump the minimal hardware requirement
for all UD<n> accordingly.
Jan Beulich [Fri, 13 Jun 2025 06:40:01 +0000 (08:40 +0200)]
gas: switch convert_to_bignum() to taking just an expression
Both callers, despite spelling things differently, now pass the same
input for its 2nd parameter. Therefore, as was supposed to be the case
anyway, this 2nd parameter isn't needed anymore - the function can
calculate "sign" all by itself from the incoming expression. Instead
make the function return the resulting value, for emit_expr_with_reloc()
to consume for setting its "extra_digit" local variable.
Jan Beulich [Fri, 13 Jun 2025 06:39:44 +0000 (08:39 +0200)]
gas: also maintain signed-ness for O_big expressions
Interestingly emit_leb128_expr() already assumes X_unsigned is properly
set for O_big. Adjust its conversion-to-bignum to respect the incoming
flag, and have convert_to_bignum() correctly set it on output.
It further can't be quite right that convert_to_bignum() depends on
anything other than the incoming expression. Therefore adjust
emit_expr_with_reloc() to be in line with the other invocation.
This also requires an adjustment for SH, which really should have been
part of 762acf217c40 ("gas: maintain O_constant signedness in more
cases").
Jeremy Drake [Fri, 13 Jun 2025 05:52:47 +0000 (07:52 +0200)]
ld,dlltool: move read-only delayimp data into .rdata
This allows the delay IAT to be in its own section with nothing else, as
required by IMAGE_GUARD_DELAYLOAD_IAT_IN_ITS_OWN_SECTION, documented at
https://learn.microsoft.com/en-us/windows/win32/debug/pe-format#load-configuration-layout
Signed-off-by: Jeremy Drake <sourceware-bugzilla@jdrake.com>
LIU Hao [Fri, 13 Jun 2025 05:52:29 +0000 (07:52 +0200)]
bfd,ld,dlltool: Emit delay-load import data into its own section
A delay-import symbol (of a function) is resolved when a call to it is made.
The delay loader may overwrite the `__imp_` pointer to the actual function
after it has been resolved, which requires the pointer itself be in a
writeable section.
Previously it was placed in the ordinary Import Address Table (IAT), which
is emitted into the `.idata` section, which had been changed to read-only
in db00f6c3aceabbf03acdb69e74b59b2d2b043cd7, which caused segmentation
faults when functions from delay-import library were called. This is
PR 32675.
This commit makes DLLTOOL emit delay-import IAT into `.didat`, as specified
by Microsoft. Most of the code is copied from `.idata`, except that this
section is writeable. As a side-effect of this, PR 14339 is also fixed.
Reference: https://learn.microsoft.com/en-us/windows/win32/secbp/pe-metadata#import-handling Co-authored-by: Jeremy Drake <sourceware-bugzilla@jdrake.com> Signed-off-by: LIU Hao <lh_mouse@126.com> Signed-off-by: Jeremy Drake <sourceware-bugzilla@jdrake.com>
Klaus Gerlicher [Thu, 12 Jun 2025 15:37:50 +0000 (15:37 +0000)]
gdb, linespec: avoid multiple locations with same PC
Setting a BP on a line like this would incorrectly yield two BP locations:
01 void two () { {int var = 0;} }
(gdb) break 1
Breakpoint 1 at 0x1164: main.cpp:1. (2 locations)
(gdb) info breakpoints
Num Type Disp Enb Address What
1 breakpoint keep y <MULTIPLE>
1.1 y 0x0000000000001164 in two() at main.cpp:1
1.2 y 0x0000000000001164 in two() at main.cpp:1
In this case decode_digits_ordinary () returns two SALs, exactly matching the
requested line. One for the entry PC and one for the prologue end PC. This
was
tested with GCC, CLANG and ICPX. Subsequent code tries to skip the prologue
on these PCs, which in turn makes them the same.
To fix this, ignore SALs with the same PC and program space when adding to the
list of SALs.
This will then properly set only one location:
(gdb) break 1
Breakpoint 1 at 0x1164: file main.cpp, line 1
(gdb) info breakpoints
Num Type Disp Enb Address What
1 breakpoint keep y 0x0000000000001164 in two() at main.cpp:1
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Andrew Burgess [Wed, 11 Jun 2025 09:20:17 +0000 (10:20 +0100)]
gdb: convert linux-namespaces debug to the new(er) debug scheme
Convert 'set debug linux-namespaces' to the new(er) debug scheme. As
part of this change I converted the mnsh_debug_print_message function,
which previously printed its output, to instead return a std::string,
this string is then printed using linux_namespaces_debug_printf. The
mnsh_debug_print_message function is only used as part of the debug
output.
I also updated one place in the code where debug_linux_namespaces, the
debug control variable, which is a boolean, was assigned an integer.
When debug is turned on then clearly the output is now different, but
in all other cases, there should be no user visible change in GDB
after this commit.
Richard Ball [Thu, 12 Jun 2025 00:39:24 +0000 (01:39 +0100)]
aarch64: Add support for FEAT_FPRCVT
FEAT_FPRCVT introduces new versions of previous instructions.
The instructions are used to convert between floating points and
Integers. These new versions take as operands SIMD&FP registers
for both the source and destination register. FEAT_FPRCVT also
enables the use of some existing AdvSIMD instructions in
streaming mode. However, no changes are needed in gas to support this.
projects / thirdparty / binutils-gdb.git / log
